Discharge means for containers or vertical retorts



D. STEWART Aug. 4, 1959 DISCHARGE MEANS FOR CONTAINERS OR 'VERTICAI.RETORTS Filed Jan. 16, 1956 3 Sheets-Sheet 1 HTTaENEYS.

Aug. 4, 1959 D. STEWART 2,397,983

DISCHARGE MEANS FOR CONTAINERS 0R VERTICAL RETORTS Filed Jan. 16, 1956 sSheets-Shet 2 //v VE'A/TOE DEN/EL J TEWB/ET Aug. 4, 1959 D. STEWART2,897,983

DISCHARGE MEANS FOR CONTAINERS OR VERTICAL RETORTS Filed Jan. 16, 1956 5Sheets-Sheet 3 /A/ vz/vraz DEN/EL .5 TE WEB? 630/14 4, 4

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United States Patent cc Application January 16, 1956, Serial No. 559,339

Claims priority,application Great Britain January '17, 1955 3 Claims.(Cl. 214-18) This invention relates to an improved discharge means forcontainers or vertical retorts and to containers or vertical retorts, ofrectangular cross-section, equipped with improved discharge means.

Continuously operatedretorts-in which the flow of the contents thereofis vertically downward are usually provided at their lower ends. withcontinuously operating discharge gear whereby steady downward movementis maintained within the retort. A conventional form of continuouslyoperating discharge gear employed in vertical retorts of rectangularcross-section comprises a pair of rollers mounted with their axesparallel and in a horizontal plane, said rollers havingsurfaceirregularities, usually in the formof ribs or radial teeth, said rollersbeing driven in opposite rotational directions'such that discharge takesplace between the rollers.

In application to free moving materials or materials which tend to bondorform clinker to ajimited degree only, it is apparent that thematerials contained. in a retort are capable not only of downwardmovement but also of a degree of'lateral shift? It has been found thatby the use of conventionally driven discharge rollers, as hereinbeforedescribed, :the. rate of downward progress of materials in acontainer orretort is non-uniform at intermediate'levelsmerein.

With a view to regularising the flow it has previously been proposed toinsert baffles in retorts of rectangular cross-section but while someimprovement is obtained in this manner, the flow is, in general, stillsubstantially non-uniform in character.

According to the present invention there is provided improved dischargemeans, for a container or vertical retort of rectangular horizontalcross-section, which comprises at least one pair of rollers, havingsurface irregularities to assist movement of the material to bedischarged, said rollers being mounted with axes parallel to the sidewalls and in a horizontal plane and being pro vided with driving meansadapted to drive said rollers in such manner that the surfaces of therollers in adjacency move upwards, said discharge means being adapted todischarge materials over the outwardly and/or downwardly moving surfacesof said rollers.

Preferably the rollers are mounted with only a small clearance betweenthe upwardly moving surfaces. Preferably the rollers are mounted withoutthe inter-position of a fixed component, for example a baflle, betweenthe upwardly moving surfaces.-

According to a further feature of this invention there is provided acontainer such as a vertical retort or storage hopper comprising theimproved discharge means hereinbefore described. Preferably saidcontainer is provided with a bafile therein, said bafifle comprising apair of surfaces, each of said surfaces extending over part of the Widthof the container or retort, that is in a direction parallel to the axesof the rollers, and being inclined to the horizontal, whereby the twosurfaces in combination provide a ridge over the line of symmetry of thepair of Patented Aug. 4, 1959 rollers. Preferably said surfaces do notmeet at their upper edges, whereby a narrow gap is provided in the ridgeof the baflle, extending over substantially the full length of saidridge, to permit the passage of a poker inserted between the-rollers.Preferably a gap is left between said bafile and each end wall of theretort. Preferably the baflle is secured to the side walls by extensionsoffering relatively small resistance to or deflection of the flow of thematerials.

Preferably the battle is provided with sloping end plates, essentiallyof triangular form, the baffle thus having the overall form of a bevelended triangular prism.

- The flow of materials through the retort is further improved by theprovision of deflectors in the vertical edges of said retort to minimisethe retarding efiect of corners formed by the adjacent walls.

Preferably the side walls (that is the longer side walls as distinctfrom the end walls) of the retort are sloped inwardly at their lowerends, preferably by an arrangement of louvres or baffle plates, asuitable clearance being provided between the lower end of each wall anda roller to provide controlled discharge therebetween on rotation of therollers.

Containers, including vertical. retorts, according to the presentinvention'are suitable for containing or treating any material in theform of separate lumps or particles 4 terials which require a constantresidence time..- The invention is of particular value in retortingcrushed minerals, such as shale, wherein a relatively long residencetime leads to undesirable sintering with blockage of the retort 'and 'arelatively short residence time results in only partial re'inoval of therequired volatile products. Furthermore, by. the .use. of dischargemeansof the presentinvention, crushing of the material being dischargedis.reducd a'r'idilesspower isrequired for the operation ;of saiddischarge means.

The invention is further illustrated but in no way limited withreference to Figures 1-5 accompanying the specification.

Figure l is an end view, half in section along the line A-A', of avertical shale retort of rectangular horizontal cross-section.

Figure 2 is a plan of the baffle 12 of Figure 1.

Figures 3, 4 and 5 are isometric views of the gas inlet section,discharge section and top section respectively, which make up the retortbase and discharge gear of the retort shown in Figure 1.

With reference to said figures:

The framework 1 of the discharge (or bottom) section (shown in Figure 4)supports and is bolted to the framework 2 of the gas inlet (ormiddleysection (shown in Figure 3) which in turn is welded to the topsection 26 (shown in Figure 5) forming the base of the retort. The mainbody 4 of the retort resting in the topmost section 26 is supported byexternal girders 3. Fire brick and insulation packing 28 are supportedby external wall 29.

Serrated cylindrical rollers 5 and 6 are supported in laterallyadjustable external bearings (not shown) the ends of the rollers passingthrough the end plates 7 and 8 by slot shaped openings 9. The clearancebetween rollers 5 and 6 is selected to prevent the discharge of shale,other than fines, therebetween, the bulk of the shale being dischargedbetween the roller 5 and side wall 10 and between roller 6 and side wall11.

Regularity 0f downward movement of the shale over the cross-section ofthe retort is provided by bafile 12, shown in detail in Figure 2. Thebaffle provides two sloping surfaces 13 and 14 secured to slopingtriangular length of the ridge of the bafiie. The baffle 12 is supportedby transverse horizontal bars 18, having chamfered upper surfaceswhereby lodging of shale thereon is minimised, said bars 18- beingcarried bythe sloping'sid walls 19 and attached to the baflieby-vertical plates. 20 and strengthening pieces 21. Below the level of'the baffle 12 are provided side louvre plates 22 of T crosssectionsupported by the end walls of the section shown in Figure 3. Behindlouvre plates 22 are provided gas inlet ports 23 having deflectors 24protecting-their inner extremities. Below the louvre plates 22" areprovided smaller louvre plates 25 supported by' the end walls of thesection shown in Figure 4.

Side walls 19 and louvre plates 22 and 25- constitute converging guideplates having openings to admit gas introduced to the retort base byports 23.

Side walls 19 and louvre plates 22 constitute components of the gasinlet section, shownin Figure 3-. Louvre plates 25 constitute componentsof the discharge section, shown in Figure 4.

The rollers 5 and 6. are driven by any suitable, source of rotary powerwhereby, from the viewpoint of Figure 1, roller 5 rotates anti-clockwiseand roller 6 rotates clockwise and whereby spent shale is passed betweensaid rollers and louvre plates 25 and discharged between the rollers andside walls and 11. v 7

Within the main body of a retort having discharge gear as hereinbeforedescribed with reference to Figures 1'-5, the downward movement of theshale is maintained very uniform, within an improvement in retortingefl'iciency.

With further reference to Figures 1-4', the following dimensionsrepresent preferred features of a shale retort having a main bodyinternal horizontal cross-section measuring 4 ft. x 8 ft.: 1 I

Length of members 13 and. 14:

Distance between member 13 and sidewall--. 1 ft. 2 in. Member 14 andside wall 1 ft. 2 in. Height of base of baffie 20 above top of Iclaim: 1. A vertical retort of rectangular cross-section having, at thebottom thereof, a gas inlet section and, below said gas inlet section, adischarge section, said discharge section comprising a pair of rollers,said rollers having surface irregularities. to assist movement of thematerial to be discharged, being..mounted with, axes parallel to theretort side walls and i'n'a horizontal plane and being provided withdriving means adapted to drive said rollers in such manner that thesurfaces of the rollers in adja- 'cency move upwards, said gas sectionhaving gas inlet ports and comprising side walls-and louvre platestogether constituting converging guide plates having openings foradmitting gas to the retort introduced by said gas inlet ports; and, abaflle, disposed in said gas inlet section, said baffle comprisingsurfaces inclined to the horizontal providing a ridge over the line ofsymmetry of the pair of rollers.

t 2. A retort as specified in claim 1 in which said baflle has a narrowgap between the surfaces constituting said bafiie and extending oversubstantially the full length of the ridge of said baffle. g

3. A retort as specified in claim 2 in which the baflle has the overallform of a bevel ended triangular prism.

References Cited in the file of this patent V UNITED STATES PATENTS353,727 Woodbury Dec. 7, 1886 1,032,132 Gormley July 9, 1912 2,753,085Plummer July 3,, 1956 FOREIGN PATENTS 471,410 Germany Feb. 12, 1929

